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 Pelican Parts: Original German
911/928 Prototype Blueprint


    Pelican Parts has acquired and scanned an original German Porsche 911/928 Prototype Blueprint.  The print was created in 1971, and has a 911 part number on the drawing.   Despite this link to the 911, the shape and form of the 928 is clearly visible.   If you look closely, you can see the rear engine watercooled 8-cylinder motor with radiators mounted in the front.  Also note the dual batteries up front.  If you have any more info or details on this print, please feel free to email us with your comments.

Leonard Laub writes:

If you read the fine print, it shows an alternate engine position (a little further back) for use with an automatic transmission. The rear view of the engine shows an air conditioning compressor. The main title calls for the V8 engine to be five to six liters. That’s one sizable water radiator up front. Clearly, Porsche was ready to build, or at least consider building, a big, comfortable, powerful, water-cooled car.

However, the plan view shows the steering wheel axis (and the orientation of the driver) tipped off the main axis of the car, as in 911s and 356s, for the same reason, namely the encroachment of the front wheels’ steering clearance into front passenger foot area. The front engine location of the 928 fixed this, along with what would have been a serious balance and polar moment issue with that nice big engine hanging out the rear.

Toward that end, note how the half shafts run diagonally back to the wheels in order to get the CG a little further inside the wheelbase. Nice try guys, but the next one was a winner.

Thanks to Pelican Parts for sharing this treasure with us.

That nifty drawing of a rear-engined V8 Porsche has a bit more to reveal. It’s dated June 12, 1971 (and signed; anyone know Herr Gerber?) a period referred to in the book "Project 928" as one in which "development chief Helmut Bott had undertaken an extensive evaluation of engine placement and drive line models", of which this appears to be one.

The book also indicates that Porsche had rejected a mid-engine layout because "There was not enough space under the rear seat for the large, eight cylinder engine they preferred." At any rate, the results of this evaluation were boiled down to the front engine, rear transaxle layout of what became the 928 and presented to Dr. Ernst Fuhrmann, the then-head of Porsche and the man we have to thank for our cars, on his birthday, October 21, 1971.

The first photo in the book shows Wolfgang Eyb, design boss for the project, signing a schematic drawing of the car labeled "Sportwagenprojekt ‘K’" (any comparison to the "Progr. ‘H’" indication on the Pelican Parts drawing?) on March 19, 1972.

Meanwhile, something a bit distressing seems to have happened, because the June ‘71 drawing not only gives the engine’s displacement as 5-6 liters but also shows two cams on each cylinder bank. By late 1972, according to "Project 928", the 928’s engine had been set with one cam per bank; the Arab oil embargo led to the capacity being brought down to 4.5 liters.

Leonard Laub (leonard@visionthree.com)
‘87 928 S4 stick (black and ever so slightly enhanced)
928 Owners Club (http://www.928s4vr.com/928OC.html)
PCA Metro New York Region


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